Attachment for a removable bridge or partial denture



H. WEISS 1 Aug. 20, 1957 ATTACHMENT FOR A REMOVABLE BRIDGE OR PARTIAL.DENTURE Filed Aug. 12,' 1953 29" IFINVEIIVIOR. L Harry We/ ss fla Afiomeys United States ATTACHMENT FOR A REMOVABLE BRIDGE OR PARTIALDENTURE This invention relates to removable partial dentures and moreparticularly to improvements in attaching devices therefor.

A partial denture may comprise one or more artificial teeth attached tonatural supporting or so-called pier teeth. Such a denture, hereinafterreferred to as a bridge, is made removable for cleaning and adjustmentand is supported in the mouth by fastening elements fixed to itsopposite ends which are adapted for engagement with the adjacent pierteeth or with complementary fastening elements anchored thereto.

The desiderata of attaching devices are well known. The bridge should bereadily removable and easily inserted but when in place should be heldsecurely so that it does not rock during the impacts of mastication.Heretofore dependence has been placed on attaching devices of aninterlocking nature connectable by a vertical sliding motion and havingparallel surfaces which must be so nicely made and aligned that there isno play between the parts when they are coupled. This being a nearlyimpossible requirement as a practical matter, and in any event arequirement which may quickly be defeated through wear, resort has beenhad to a variety of resilient structures involving the use of separatespring elements or integral springable parts. Dental metals not beingvery good spring materials, these have not been entirely satisfactoryfor that reason and for the further reason that the presence of springelements may permit relative motion between the bridge and the pierteeth.

In accordance with the invention a combination of parallel and taperedsurfaces is employed which entirely eliminates the need for springs inmaking a tight rock-proof joint, which allows for relatively great easeof movement when the bridge is slightly moved from its seated positionand hence greatly facilitates insertion and removal, which eliminatesdrift between the bridge and pier teeth and in which there will benegligible wear. Indeed, wear, which must necessarily occurin any suchstructure, will result in automatic accommodation of the surfaces toeach other so that the assembly, on each occasion that it is set up,will be snug and tight, With substantially no relative movement of theparts after they have been properly associated. The association of thesurfaces with each other results in relatively tight engagement as thetapered surfaces and the parallel surfaces act together as bearingsurfaces. In conjunction with these surfaces, means may be associated inthe form tent a pier tooth and in one end of a bridge, the two partsbeing shown as separated for clarity;

Fig. 2 is a front elevation of the male part of the attaching device;

Fig. 3 is a rear elevation thereof;

Fig. 4 is a top plan view of the same;

Fig. 5 is a top plan view of the female part of the attaching device;

Fig. 6 is a front elevation thereof;

Fig. 7 is a side elevation of the male coupling part associated withfragmentary top and bottom profiles thereof;

Fig. 8 is a central vertical sectional elevation of the female part,taken on the line 8-8 of Fig. 6; and

Fig. 9 shows a modification of the female part.

Referring to Figs. 1, 5, 6 and 8, the female part of the attachingmember, generally indicated at 10, provides a socket which is attachedto pier tooth 11 in the usual way as part of an inlay 12 cemented in theprepared tooth. Instead of an inlay a three-quarter or full crown mayprovide the base for member which, according to well known technique,will become an integral part of the inlay or crown.

Referring to Figs. 1, 2, 3, 4 and 7, the male part of the attachingmember, generally indicated at 15, is similarly attached to an end tooth16 of a partial denture or bridge by soldering to the metal portionthereof. Proper alignment of parts 10 and will be made by the dentaltechnician. Member 15 has a base plate 18 forming the back of the part,a forwardly extending shank 19 and an enlarged head portion having, fromfront to back, an outer face 20, a pair of outer side faces 21, a pairof first inner faces 22, a pair of inner side faces 23, and a pair ofsecond inner faces 24, faces 21-24 being in stepped arrangement. Shank19 is flush with the head portion at the top and is shorter at thebottom so that the head portion has an overhang 25 (Fig. 7).

As may best be seen in Fig. 7, the front face of base 18 and first innerface 22 extend in parallel directions. The next two faces 23 and 24taper downwardly and forwardly, away from base 18, forming wedgingsurfaces. Outer face preferably has a slight downward and rearward tapertoward base 18 for clearance purposes which gives it too a slight wedgeshape. Faces 21 and 23 and shank 19 preferably have a slight taper fromtop to bottom, though the sides of the shank may be practically parallelwith a less pronounced taper than the taper of said faces.

The socket or female part 10 has an aperture shaped to correspond to theshape of the head portion and shank 19 of part 15, which apertureextends inwardly from and opens through the flat front face 26, which,when the parts are joined, lies flat against the front face of base 18of male part 15. The walls of the aperture bear numbers corresponding tothe numbers on the male part, distinguished by being primed. Thisaperture, as seen in Fig. 8, pro-vides a socket 27 at the bottom whichreceives the overhang 25. As male part 15 moves into female part 10,there will be a loose fit as overhang 25 enters socket 27. Any foodparticles, either in the liquid or semi-liquid state, which may havebecome trapped in this socket, will be expressed out of the socketaround the walls of the overhang until the overhang finally comes torest firmly seated in the socket. However, this socket, if desired, maybe open at the bottom to permit discharge of food particles, as shown at27a in Fig. 9. It will also be seen that the bottom end of female part10, in either embodiment, is of a very rigid construction, a continuousbridge 28 of metal integral with the side walls extending across thefront of socket 27 or 27a. Just below this bridge face 26 is providedwith a transversely elongated depression or .recess29. I

As may be seen in Figs. 1, 2 and 3, the lower portion of base 18 of part15 is slotted beyond the outer boundaries of shank 19 at 30, 31, 32 toform two spring arms 34, 35 which have on their front faces elevations34a, 35a which engage in recess 29. The positions of the elevations andthe recess could, of course, be reversed. Arms 34, 35 can be bent toprovide the desired degree of spring pressure toward said recess toprovide a snap lock when the parts and are fully interengaged or so bentas to eliminate such lock as to either or both of the arms. The springaction is illustrated in the dotted line position of arm 35 in Fig. 7.

It will be understood that in mounting part 15 on denture 16 the arms34, 35 will be left free to move by having appropriate clearance withrespect to the denture, the area of attachment being restricted to thatportion of the base 18 above slots 32. These slots provide againstpossible accidental union of arms 34, when the denture is beingattached, and thus the arms posi- I tively are left free.

It will be noted that the cross slot joining slots 30 and 31 isapproximately opposite the lower end of shank 19 and together with slots30 and 31 provides an opening through which any expressable matter,which may have accumulated in the socket of the female part, may beexpelled as the overhang 25 moves into socket 27 and as the elevations34a and 35a snap into the groove 29. Also, said elevations are so placedon the spring arms 34 and 35 and are of such extent that as the partsare moved relatively into locking position the elevations ride on theface 26 of the female part until they reach the groove 29.

Considering the details above described it will be evident that thebasic structure comprises a male member with'a generally wedge-shapedsolid member carried on its shank, its inner and outer walls beingnon-parallel, and a female member with a corresponding wedge-shapedrecess behind the groove which receives the shank. The locking means iswholly external to the recess and functions only to hold the wedge inseated position. By eliminating all spring devices from the wedge andrecess, the connection is unyielding; yet upon slight movement,sufficient only to move the elevations 34a and 35a out of groove 29, theparts move very freely making removal very easy.

The embodiment above described as an illustration of the inventionincludes details which are subject to omission or variation and theinvention is not to be considered as limited thereto but is to beconstrued only in accordance with the appended claims.

What I claim is:

1. An attachment for partial dentures of the type having separable maleand female parts interengageable by relative sliding motion, whereinsaid male part has a base, a shank and an enlarged head portion,characterized by said base and said head portion having opposed planesurfaces extending in parallel directions, and intermediate wedgingsurfaces extending outwardly of said shank; said female part having anaperture shaped to conform to said shank and head portion and adapted toreceive the same, and having a flat front face adapted to bear againstthe plane surface of said base.

2. The attachment of claim 1 wherein said base is provided with anintegral resilient arm, and said arm and said fiat front face areprovided with interengaging locking means adapted to yieldably resistsliding separation of the interengaged attachment parts.

3. The attachment of claim 2 wherein said locking means comprises anelevation on said arm and a recess in said flat front face.

4. Attaching means for securing a partial denture to a pier tooth, ofthe type having separable male and female parts interengageable byrelative sliding motion, wherein said male part has a base, a shank andan enlarged head portion, characterized by said base and said headportion havingopposed plane surfaces extending in par allel directions,said head portion having intermediate wedging surfaces extendingoutwardly of said shank and having generally a slight taper from top tobottom; said female part having an aperture shaped to conform to saidshank and head portion and adapted to receive and closely surround thesame when the parts are coupled, and having a flat front face adapted tobear against the plane surface of said base; whereby the parts areloosened on slight separating movement.

5. An attachment for a bridge of the type having separable male andfemale parts interengageable by relative sliding motion, wherein saidmale part has a base, a shank and an enlarged head portion characterizedby said base and said head portion having opposed plane surfacesextending in parallel directions, said head portion having a steppedconfiguration inwardly of its edges toward said shank, one of the stepsproviding an intermediate wedging surface; said female part having anaperture shaped to closely fit around said shank and head portion andadapted slidably to receive the same, and having a fiat front faceadapted to bear against the plane surface of said base and a slopinginternal surface providing a wedging action with said wedging surface asthe parts are coupled together.

6. Attaching meansfor securing a partial denture to a pier toothcomprising interengageable male and female parts, said male part havinga shank and a solid head portion carried thereby, said head portionhaving a plurality of at least four longitudinal surfaces, at least twoof such surfaces sloping progressively inwardly toward the longitudinalaxis of said head to provide a wedge shape, and at least two othersurfaces of said head member being disposed at substantially uniformdistances from said longitudinal axis throughout the length of saidhead; said female part having a recess provided with substan tiallyrigid complemental surfaces adapted to closely engage said head portionwhen the parts are fully engaged and a slot to receive said shank.

7. Attaching means for securing a partial denture to a pier toothcomprising interengageable male and female parts, said male part havinga shank and a solid head portion carried thereby, said head portionhaving a plurality of at least four longitudinal surfaces, at least twoof such surfaces sloping progressively inwardly toward the longitudinalaxis of said head to provide a wedge shape, and at least two othersurfaces of said head member being disposed at substantially uniformdistances from said longitudinal axis throughout the length of saidhead; said female part having a recess provided with complementalsurfaces adapted to closely engage said head portion when the parts arefully engaged and a slot to receive said shank; and resilient lockingmeans carried by said male and female parts adapted to interengage uponthe seating of said wedge-shaped head portion in said recess.

8. Attaching means according to claim 7 wherein said locking meanscomprises a projection on one of said parts and an indentation on theother of said parts.

9. Attaching means according to claim 7 wherein said locking meanscomprises a spring finger on one of said parts carrying a projection tobe interlocked with an indentation on the other of said parts.

10. Attaching means according to claim 7 wherein said locking meanscomprises a pair of spring fingers on said male part integral with awall thereof, each finger having a projection, said female part having agroove to receive said projections.

11. An attachment for a partial denture, the attachment consisting of apair of interengageable sections, one of the sections of the attachmentbeing intended to be associated with a pier tooth and the other sectionbeing intended to be associated with the partial denture, one of thesections having a recess therein, a Wall for that section as oneboundary for the recess, the inner faces of the recess being defined bysurfaces all vertical lines in which are straight and uninterrupted, thewall having a slot extending therethrough from the recess, the othersection being formed to interfit with the recess and having meansextending through the slot, and an interlockable indentation andprojection carried by the sections to be interlocked as the sections aremoved into the interengaged relationship to retain the sections againstseparation from the interengaged relationship, the indentation beinglocated on one section and the projection on the other section so thatcommunication between the recess and the slot remains open to permitejection of foreign material from the recess by the other sectionsubstantially until the indentation and the projection move intointerlocking relationship.

12. An attachment for a partial denture, the attachment consisting of apair of interengageable sections, one of the sections of the attachmentbeing intended to be associated with a pier tooth and the other sectionbeing intended to be associated with the partial denture, one of thesections having a recess therein, a wall for that section as oneboundary for the recess, the wall having a slot extending therethroughfrom the recess, the wall having an indentation therein below the slot,the other section being formed to interfit with the recess and havingmeans extending through the slot, and the other section having aseparation to provide a projection to be interlocked with theindentation as the sections are moved into the interengaged relationshipto retain the sections against separation from the interengagedrelationship, the projection being associated with the other section sothat the separation provides a passage for movement of foreign materialfrom the recess by the other section, the separation being positioned toprovide such access until the indentation and the projection move intointerlocking relationship.

13. An attachment for a partial denture, the attachment consisting of apair of interengageable sections, one of the sections of the attachmentbeing intended to be associated with a pier tooth and the other sectionbeing intended to be associated with the partial denture, one of thesections having a recess therein, a wall for that section as oneboundary for the recess, the wall having a slot extending therethroughfrom the recess, the wall having an indentation therein below the slot,the other section being formed to interfit with the recess and havingmeans extending through the slot, and the other section having a fingerat its lower extent, thefinger carrying a projection, the projectionbeing positioned to ride on the wall and leave the slot open as thesections are moved into the interfitted relationship, the projection andindentation becoming interlocked as the sections are moved intointerfitted relation to restrain the sections against separation.

14. Attaching means for securing partial dentures to pier teeth, theattaching means comprising interengageable male and female parts, saidmale part having a shank and a solid head portion carried by the shank;the female part having a recess formed to be complementary to the headportion, the female part being adapted to receive the male part seatedin the recess and then closely to engage the head portion, the femalepart having a slot, the shank extending through the slot when the headportion is seated in the recess, one of the parts having a projectionand the other part having an indentation, the projection and indentationbeing located to interengage with each other outside of the recess whenthe head portion is seated in the recess and then to function to retainthe head portion seated in the recess.

15. Attaching means for securing partial dentures to pier teeth,comprising interengageable male and female parts, said male part havinga shank and a solid head portion carried by the shank; the female parthaving a recess formed to be complementary to the head portion, thefemale part being adapted to receive the male part seated in the recessand then closely to engage the head portion, the female part having aslot, the shank extending through the slot when the head portion isseated in the recess, one of the parts having a pair of spring fingers,projections and indentations carried by the spring fingers and the otherpart to interengage with each other outside of the recess when the headportion is seated in the recess and then to function to retain the headportion seated in the recess.

References Cited in the file of this patent UNITED STATES PATENTS1,520,809 Cohen Dec. 30, 1924 1,522,233 Feinberg Jan. 6, 1925 1,645,340Moore Oct. 11, 1927 1,705,504 Sorensen Mar. 19, 1929

